HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sala, R. G. Articles by Westgate, M. E. Search for Related Content PubMed Articles by Sala, R. G. Articles by Westgate, M. E. Agricola Articles by Sala, R. G. Articles by Westgate, M. E. Related Collections Crop Physiology & Metabolism Maize

CROP PHYSIOLOGY & METABOLISM

Maize Kernel Moisture at Physiological Maturity as Affected by the Source–Sink Relationship during Grain Filling

^a CONICET, Unidad Integrada INTA Balcarce-Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Ruta Nacional 226 km 73.5, CC 226 (7620) Balcarce, Buenos Aires, Argentina
^b Dep. of Agronomy, 1301 Agronomy Hall, Iowa State Univ., Ames, IA 50010

^* Corresponding author (salarode{at}yahoo.com.ar).

A wide range of values reported in the literature has precluded the use of grain moisture (GM) as an estimate of physiological maturity (PM) in maize (Zea mays L.). The reason for this variability in GM values remains unclear. Previous evidence suggests that the source–sink ratio could affect the dynamics of kernel water relations during grain filling and thus, GM at PM. To test this possibility, treatments were applied to manipulate the reproductive sink capacity or the assimilate availability during grain filling. Kernel dry weight, water content, and the dry weight to water content (D–W) ratio, were monitored throughout grain filling. A bilinear model relating dry weight and GM was used to estimate GM at PM for each treatment. Severely restricting source capacity during grain filling increased GM at PM. When the source capacity per kernel during grain filling was increased, however, GM at PM was not affected. A single model (r² = 0.99, p < 0.001) described the relationship between relative dry weight and GM for all hybrids and treatments without source reduction during grain filling. The estimated value of GM at PM for this model was 34.9%. These results suggest that calculating GM late in grain filling can provide a reliable estimate of PM when the source capacity has not been severely restricted. A value of 35% moisture would be adequate in these situations. The D–W ratio of developing kernels was similar across all source–sink treatments until PM. Premature cessation of grain filling caused by defoliation increased the D–W ratio as the kernels continued to desiccate.

Abbreviations: D–W, dry weight to water content • GDD, growing degree days • GM, grain moisture • PM, physiological maturity • PWGK, plant weight gain per kernel.